Getting JJ KT88s for Model T

[gray]

I'm getting a quad of JJ KT88s for my 70's Model T, and they should be here an a couple of days. However, I was just told today a story of a guy who put some in a Fender amp and that they melted. Is this some kind of danger I never knew about? I've only read good things about JJ KT88s. I have some pretty important shows coming up soon and I don't need a flaming amp. Is this melting business just an old wives tale?

[stanner]

YEP

[red]

In my experience, the JJ tubes have always been really nice quality.  If they melted in someone's amp, the chances are there was another problem he didn't know about before hand.  Just make sure you check the bias and you should be fine.

[gray]

That's what I thought, that the only way someone's tubes could have done that would be if they were biased wrong, like if they were just switched from amp to amp without biasing them correctly.

[JoeArthur]

 

When any story gets repeated through enough people, it eventually gets mangled.

I have know a couple of fools that thought they could get more power out of their Fender by swapping in 6550s or KT-88s.  After all people swap preamp tube types that are pin compatable all the time, why not power tubes?

Well, they found out when the heater winding in their power transformer essentially melted, destroying it.

6L6 tubes used in most Fenders draw 0.9 amps of heater current.  6550 types draw 1.6 amps of heater current.

The tubes of course wouldn't have had any problem, but some people would rather blame "bad tubes" than admit their own stupidity.

[gray]

Aha, I knew it was something like that. I think you're right, too, about people being unwilling to admit fault. At any rate, Eurotubes delivered the ol' KT88s today, and I have a couple leads on who can install them for me, as I'm about as qualified to do it as I am to be a lion tamer. Thank you all for your information and I'll be sure to post the results.